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mOLlmmq/UUUW NO NOLINMLDUMW OP Rlnh vLlLJL A. L. CULBERTSON May 17 1932 HEATING FURNAcE Original Filed Jan. e, -1929 N @WN M5567 .L CULEEETsO/V,

' Reissued May 17, 1932 UNITED STATES PATENT v'or-FICE .ALBERT L. CULBERTSON, 0F MOUNT LEBANON, PENNSYLVANIA; LAVERNA. M. CUL- IBERTSON' AND THE UNION TRUST COMPANY 0F PITTSBURGH EXECUTOBS OF SAID ALBERT L. CULBERTSON, DEGEASED HEATING FURNACE Original No. 1,789,966, dated January 27, 1931, Serial No. 331,015, led January 8, 1929. Application for reissue led March 30, 1931. Serial No. 526,507.

This invention relates to heating furnaces and method of firing said furnaces and, while not limited thereto, relates more particularly to heating furnaces particularly adapted for heating billets, sheet bars and the like, and to a novel method of firing said furnaces whe-reby the material being heated may be heated by both radiation and contact with the iame.

the exit or forward end of the combustion chamber'.

Another object is to provide a furnace of this class in which the maintenance cost will be materially reduced since the flame isdirected against the forward wall of the combustion chamber which is open and free to complete circulation of air.

A further object is to provide a furnace having materially increased eiiiciency over furnaces of the prior art wherein the flame travel is in a single direction over the material being' heated.

In the drawings- Figure 1 is a longitudinal sectional view through a furnace constructed in accordance with this invention and adapted to carry out this novel method. v

FigureQ is atransverse sectional elevation taken von the line II-II of Figure 1.

Referring more particularly to the drawings, the numeral 2 designates the furnace hearth which is of the usual horizontal construction and is provided with skid members 3 and 3a. The skid members 3 are water cooled while the skid members 3a are solid uncooled members.

A low enclosing structure 4 is provided overthe hearth 2 from the rear or entering end forwardly for a material distance and` forms a low channel portion or heating chamber 5. q The rear end of the enclosing structure 1 1s provided with an opening 6 through which the material to be heated is charged into the furnace.

Forward of the enclosing portion 4 an enclosing portion -7 isV provided which is built up a material distance above the portion 4 and extends forwardly to the forward or discharge end of the furnace and forms a com-` bustion chamber 8. r[he ends ofthe chamber 8 are closed by rear and forward end walls 9 and 10, respectively. The forward end wall- 10 is provided with an opening l2 through which the heated material is discharged.

A vertical flue 13 is provided at the rear end of the chamber and extends downwardly and connects with a horizontal flue 14 which extends forwardly under the furnace and delivers the products of combustion and heated gases to any suitable recuperator or regenerator (not shown) which is adapted to supply preheated air to the burners of the furnace.

` The rear wall 9 of the combustion chamber 8 isA provided with a plurality of gaseous or liquid fuel burners 16 at a point adjacentV the top of the wall 9 and chamber 8. The burners 16 are adapted to receivefuel through the pipe 17. and to have preheated air delivered thereto from a main conduit 18 and branch conduits 19.

It will be understood that this invention is not limited to the use of gaseous or liquid fuel burners in the chamber 8, since any fuel burners capable of delivering the flame volume may be used, also any number of burners may be used.

It will be understood that I do not wish to be limited to the use of 'one vertical combustion chamber 8 since more than one may be provided, if desired, and also, if desired, means may, 1n addition, be provided for underfrlng 1n the ordinary manner so as to impinge a fiame against the underside ofthe materialbeinggheated.

The operation of the above described furnace when carryingout the method of this invention is as follows:

Assuming thatthe furnace is charged and in'operation, the flame from the burners `16 will be forced forwardly in a substantially horizontal of the com .ustion chamber 8 until it strikes the forward wall 10of the chamber, which wall will force the flame-body to turndown wardly toward the furnace hearth 2 and the ame will then be compelled to flow rearwardl in seeking an escape in a direction opposi to that of the movement of the maheated. This rearward fio'w or terial l travel of t e flame will be aided materially by the draft from the iues 13 and'14 and the flame will thus'be drawn the entire length of the furnace hearth.- By causing a reverse flow of the dame-body so that the upper and lower portions thereof are owing 1n oppo' site directions, a vvertical horse-shoe 'sha d traveling flow-body of flame is provide in the combustion chamber 8 above the material being heated. The u per or forwardly traveling portion of the ow body of flame is the hottest and the lower or rearwardly traveling ortion is the coolest; Therefore the coolest ame is in .contact with the metal beingi heated while the hottest flame is separated by the cooler ame from the metal and heats the metal by radiation only.

B provlding this novel flow of the flame, the ength of flow for a given length of cornbustion chamber is increased, the hottest flamel is yprevented from impinging directly on the metal, a more uniform temperature throughout the combustion chamber is had,-

- and a soaking condition is provided since the hottestflametemperature is over the cool metal as it enters the combustion chamber,

vand both the gases and steel are substantially ata uniform temperature. at the forward or dischar end of the furnace.

Anot er feature resulting from the novel method offiring of'this invention is that the wall 10 'against which the flame impinges is free to have a complete circulation o air over its outer'surface. Therefore saidwall will have a materially increased life and maintenance cost will materially reduced over that resulting whenV the flame is directed against the rear wall, as is ordinarily the practice.l P

' A still further advantage resulting from the. novel method of firing of this 'application is that the infiltration of cold air through the discharge port or opening 12 is substantially prevented due to the force of the'flame at this point.

Many other advantages result from my novel method and will be apparent to those skilledintheart.' v

While I have shown and described one speciic'embodime'nt of my invention it will be 1 undrstoodthnt I do not wish mbe limitedthereto, since various 'modifications may be made without departing from the scope of lane through the upper portion.

my invention as claims.

I claim: 1. A- continuous heatin ing billets, sheet bars an the like comprisdefined in the appended ing top, bottom, side and end walls, `said top wall being stepped' upwardly from a furnace for heatpoint intermediate the ends of said furnace to one end wall to form a hi h 'combustion chamber of more than oneird the total length ofthe furnace, the end wall farthest from s'aidhigh combustion chamber being provided with an inlet port throuv h which the material to be heated enters saidg furnace, the other end wall closing the forward end of said high combustion chamber being provided with an outlet vport opening to the atmospherethrough which the heated material is discharged, at least one fuel burner mounted in the back wall of said high combustion chamber adjacent the top thereof and directing a flame against the forward end wall of said furnace, and a flue connection adjacent the rear or entering end of said furnace, said flue communicating with the interior of saidrfurnace through the bottom wall thereof below the material being heated, said burner and said iiue being arranged to cause the flame after being projected to-4 ward the forward end wall of sa1dl furnace to reverse and ilow back alonsaid furnace under the dame body issuing rom said burner and then continue rearwardly in contact with the material to be heated throughout the length -of said furnace.

2. A continuous heatin furnace for heating billets, sheet bars and thelike com rising top, bottom, side and end walls, sai top wall being stepped upwardl from a point intermediate the ends of sai furnace to one end wall to form a hi h combustion chamber of more than one-thir the total length of the furnace, the end wall farthest fromsaid high combustion chamber being provided with any inlet port through which the material to be heate enters saidy furnace, and the other -end wall closing the forward end of said' high Vcombustion chamber being lprovided with an 'outlet port o ening to the atmos# here through which the heated material is dischar d, at least one fuel burner mounted in the ack wall of1 said high combustion chamber adjacent the top thereof and adapted to direct a flame toward the forward end wall of said furnace, anda flue connection adjacent the rear or entering end of said furnace, said burnerr and said iluejbeing ar-v rangedto cause the fiame'after being prolao jected toward theforward end wall of said furnace to reverse and How back along said furnace under the flame body 'issuing from said burner vand then continue rearwardly in4 contact with lthe material to'bel heated throughout -the length of said. furnace. v

3. continuous heating furnace for heat` ing billets, sheet bars and the like comprising top, bottom, side and end walls, said top Wall being stepped upwardl from a point intermediate the ends of sai furnace to one end Wall to form a high combustion chamber of more than one-third the total length of the furnace, said furnace being provided at the end farthest from the high combustion chamber with an inlet Y ort throu h which the material to be heated3 enters sai furnace, and

a discharge opening adjacent the other end of said furnace through which the heated material is discharged, at least one fuel burner mounted in the back wall of said high combustion chamber adjacent the top thereof and adapted to direct a flame toward the forward end Wall of said furnace, and a iiue connection adjacent the rear or entering end of said furnace, said flue communicating with the interior of said furnace, said burner and said flue being arranged to cause the flame after being projected toward the forward end Wall of said furnace to reverse and flow lback along said furnace under the flame body issuing from said body and then continue rearwardly in contact with the material to be heated through substantially the length of the furnace.

In testimony whereof, I have hereunto set my hand. this 23rd day. of March, 1931.

ALBERT L. CULBERTSON. 

